Red mud (RM), also known as bauxite residue, is the primary waste product generated by the Bayer process for alumina production from bauxite. Its disposal represents one of the biggest issues in the ...mining industry since the high amount produced every year. In the present paper, the synthesis and characterization of new materials obtained by reacting RM and RM/metakaolin mixtures with phosphoric acid (H3PO4) are reported. The obtained samples are characterized by excellent chemical and physical properties and superior compressive strength (up to 63 MPa), suggesting their application in the building sector. Moreover, a comparison with samples produced starting from a similar powder composition, but obtained in alkaline conditions, has been also performed. The proposed synthesis method enables the recovery of this industrial waste by producing objects with properties and characteristics comparable to existing construction materials. However, it is advisable to conduct life cycle assessment (LCA) and life cycle costing (LCC) analyses before undertaking large-scale implementation, even considering the possibility of using phosphoric acid activation procedure with the RM residual obtained after the extraction and recovery of metals and rare earth elements, widely studied for this type of waste.
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Alternative building materials have the potential to reduce environmental pressure from buildings, though the use of these materials should be guided by an understanding of the embodied environmental ...impacts. Extensive research on embodied greenhouse gas emissions from buildings has been conducted, but other impacts are less frequently reported. Furthermore, uncertainty is rarely reported in building LCA studies. This paper provides a piece for filling those gaps by comprehensively reporting the embodied environmental impacts of a fiberglass house within the LCA framework, modeled in the OpenLCA software using the Ecoinvent 3.7.1 inventory database. The ReCiPe 2016 impact assessment method is used to report a wide range of environmental impacts. The global warming potential is calculated to be 311 kgCO2 eq/m2. Additionally, a hotspot analysis is included to identify areas that should be the focus for improvement, as well as an uncertainty analysis based on Monte Carlo. The embodied emissions are given context by a scenario analysis over a 50-year use phase in three different grid conditions and with two different energy efficiency levels. Based on the results of this study, it is determined that fiberglass does not provide a viable alternative to conventional building materials if the purpose is to reduce embodied emissions from buildings.
Concrete, a widely used building material, should minimize its environmental impact to align with the construction sector's Sustainable Development Goals. Researchers worldwide are investigating the ...possibility of e-waste in building materials incorporating various recyclable elements. This paper conducts a thorough review of research on e-waste as a building material. Various E-waste products are used as fine and coarse aggregate replacements in concrete. The study uses a bibliographic approach with the Scopus database to delve into the literature discussing E-waste in construction materials from 2007 to 2022. Data are extracted specifically from Scopus, which identifies 731 papers based on the keyword "Electronic waste used as building materials". The second step involves scientometric analysis, which focuses on patterns within the articles, such as the most prolific countries, sources, frequently used keywords, and reports containing relevant research. Each research phase contains a summary of the results obtained at various stages. Detailed quantitative and qualitative discussions are also conducted to achieve the three primary goals: a summary of quantitative data, a discussion of the existing application, and identifying future research directions. These findings will be useful for subsequent academic studies on transforming e-waste into building materials. The scientometric review provides a path for researchers from various countries to share new ideas and information while encouraging research collaboration.
The benefits of eco-bricks have been highlighted in contemporary literature. Notwithstanding, the adoption of eco-bricks masonry for the construction of houses in rural communities of low-income ...countries is significantly low. This study investigated the features, benefits, drivers and barriers to eco-bricks masonry from the expert's perception. Yelwa village, where the first bottle bricks masonry building was constructed in Africa, was selected for the study. Empirical survey, interview and questionnaire design approach were used to gather data for the research. The study found that eco-bricks are used in the construction of masonry walls and columns, septic tanks, and water reservoirs, and in the construction of multistorey buildings. Door and window openings are created with wooden or metallic frames, and wall plate clits are secured with mortar. Principal drivers of eco-bricks masonry include job creation, high durability, cleaner environment promotion and high cost of conventional building materials. Inadequate skilled workers, lack of government incentives and research funding were identified as significant barriers to the propagation of bottle brick technology. This study is of value in that it can assist in the reduction of plastic waste and the housing deficit, and is also expected to inform policy deliberations and directions towards the creation of innovation-friendly environments in the housing sector.
Within Malawi, and across the Global South, the adoption of stabilised soil blocks (SSBs) as a sustainable alternative to burnt clay bricks, has been hindered by the high cost of stabilisers. The ...purpose of this article is to evaluate the performance of cement as a stabiliser in soil stabilised blocks, and to propose cement ratios which both reduce the material cost while meeting building requirements for local applications. Using a brick production method replicable within a rural African context, we tested a range of cement contents for dry compressive strength, flexural strength, and water absorption properties. Our findings suggest that a cement content of 3.6% is adequate for single-story building applications, four times lower than that currently used in compressed brick production within the study area. Moreover, the elimination of the firing process - which represents half of burnt brick production costs - and the proposed cement ratios correspond to large cost savings, ranging from 20% to 77% depending on building application, for brick producers. These results suggest that the cost of manufacturing stabilised soil blocks can be considerably reduced and thus become financially viable; however further innovation is needed to achieve a sustainable means of production and use.
Across the Global South, post-consumer waste glass is an often dumped, and under-utilised resource. Even in Malawi, with widespread return schemes, many barriers exist, inhibiting reuse, and ...necessitating appropriate solutions. The purpose of this article is to evaluate the performance of post-consumer waste glass as a coarse aggregate within burnt clay bricks, and to assess the feasibility for the recovery of this waste material from dumped stocks within Chembe. Using a brick design and testing methodology, which could be replicated within a rural African context, we tested a range of glass additions (both quantity and size of particle) for compressive strength and water absorption properties. Our results suggest that waste glass can function as a performance enhancer, with positive effects on compressive strength observed at up to 10% crushed waste glass content. These findings support existing literature on glass waste additions, yet show that optimal results can also be had with post-consumer waste glass and in low income, and less technology-reliant contexts. Moreover, our findings suggest that current above-ground stocks of waste glass are sufficient to support the production of hybrid building materials for decades, however further innovation is necessary in order to achieve a sustainable mode of practice.
RESUMO Os materiais cimentícios são os mais utilizados mundialmente, na construção civil. Frente a isso, pesquisas são necessárias para melhorar tanto seu desempenho mecânico quanto seu ...desenvolvimento sustentável. Uma alternativa que busca essas melhorias é a adição de materiais de origem vegetal, como por exemplo, a fibra de coco e a microcelulose cristalina. Sendo assim, o objetivo do presente trabalho foi avaliar a influência das adições de fibra de coco (FC) e microcelulose cristalina (MCC) nas propriedades físicas e mecânicas de argamassas cimentícias. Para um melhor delineamento da pesquisa, esta foi dividida em três fases: caracterização dos materiais; análise de argamassas com adições de FC e argamassas com adições de MCC; análise de argamassas com adições de FC e MCC simultaneamente. Foram realizados os seguintes ensaios: índice de consistência, resistência à compressão, resistência à tração na flexão, módulo de elasticidade, absorção de água, índice de vazios, massa específica, Microscopia Eletrônica de Varredura (MEV) e Espectrografia por Dispersão de Energia (EDS). Os resultados encontrados demonstram que as incorporações de FC e MCC em teores acima de 0,2FC e 0,3MCC melhoram de forma significativa o desempenho das argamassas quanto aresistência à tração na flexão, porém não contribuem de forma positiva nas outras propriedades mecânicas das argamassas, mas sem prejuízos significativos para sua utilização. É recomendável estudos de argamassas com FC e MCC a longo prazo para verificar se as propriedades mecânicas sofrem influências significativascom a idade.
ABSTRACT The cementitious materials are the most used worldwide, in civil construction. Faced with this, research is needed to improve both its mechanical performance and its sustainable development. An alternative that seeks these improvements is the addition of materials of vegetable origin, such as coconut fiber and microcellulose crystalline. Therefore, the objective of the present work was to evaluate the influence of additions of coconut fiber (CF) and microcellulose crystalline (MCC) on the physical and mechanical properties of cementitious mortars. For a better delineation of the research, it was divided into three phases: characterization of the materials; analysis of mortars with additions of CF and mortars with MCC additions; analysis of mortars with additions of CF and MCC simultaneously. The following tests were performed: consistency index,compressive strength, flexural tensile strength, modulus of elasticity, water absorption, void index, specific mass, Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The results show that the incorporations of CF and MCC in contents above 0.2CF and 0.3MCC significantly improve the performance of mortars in terms of tensile strength in flexion, however do not contribute positively to the other mechanical properties of mortars, but without significant damage to its use. Studies of mortars with longterm CF and MCC are recommended to verify if mechanical properties undergo significant influences withage.
The built environment sector causes significant climate change impacts, which indicates an opportunity for the sector to be of great importance in reducing its global impact. The main strategy has ...focused on urban density and transport as well as studying the emissions caused by buildings with life-cycle assessments (LCAs). However, a holistic approach is often missing, where life-cycle environmental impacts are assessed, and goals are considered at the planning stage. This study proposes LCA on a neighborhood scale for a holistic approach and to identify how LCA can be used to reduce impacts when designing and for decision-making at the planning stage. The focus is on the pre-use phase because that phase has been proven to cause a significant spike in carbon emissions when considering the near future and is crucial in reaching climate goals. The study case is a new neighborhood plan in Reykjavík, Iceland. The assessment focuses on the climate change impact of building a new neighborhood. The study identifies materials as a key factor. It demonstrates how the total emissions of the neighborhood are reduced when more environmentally friendly materials are replaced by traditional ones. It reduces GHG emissions by up to 40% in total.
The rapid urbanization of developed countries and the difficulty in disposing of agricultural wastes have created opportunities for the construction industry to use agricultural wastes. A wide ...variety of agricultural waste materials are already in use with concrete as substitutes for cement and aggregates, as well as reinforcing materials. This study reviews the available literature published from 1935 to 2022 on agricultural wastes being used as building materials. The research utilizes a bibliographic approach based on the Scopus database. This article retrieves data employing the Scopus database and incorporates 671 articles based on the keywords, agricultural wastes used as building materials. The scientometric analysis is the second step, wherein the patterns of the obtained articles are investigated with various factors such as countries with the most publications, sources that have the most publications, most frequently appearing keywords, and articles with more relevant research works. A summary of the results obtained at various stages of the research is depicted in each phase. Detailed quantitative and qualitative discussions are also conducted to achieve the three main objectives: the summarization of quantitative data, discussion of the existing application, and identification of future research directions. These findings serve the future endeavor of agricultural waste-to-building materials’ incineration academic research. The scientometric review paves the way for academics from various nations to impart novel ideas and information and foster research collaboration.
The existing building stock is estimated to need major renovations in the near future. At the same time, the EU energy-efficiency strategy entails upgrading the energy performance of renovated ...buildings to meet the nearly-zero energy standard. To upgrade existing buildings, two main groups of measures can be adopted: thermally-improved building envelope and energy-efficient technical devices. The first measure usually involves additional building materials for thermal insulation and new building cladding, as well as new windows and doors. A number of commercially-available materials can be used to renovate thermal building envelopes. This study compares the life-cycle primary energy use and CO2 emission when renovating an existing building using different materials, commonly used in renovated buildings. A Swedish building constructed in 1972 is used as a case-study building. The building's envelope is assumed to be renovated to meet the Swedish passive house standard. The entire life cycle of the building envelope renovation is taken into account. The results show that the selection of building materials can significantly reduce the production primary energy and associated CO2 emissions by up to 62% and 77%, respectively. The results suggest that a careful material choice can significantly contribute to reduce primary energy use and CO2 emissions associated with energy renovation of buildings, especially when renewable-based materials are used.
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